Lactide

Names
Preferred IUPAC name

3,6-Dimethyl-1,4-dioxan-2,5-dione

Other names

Dilactid

Identifiers

CAS Number

* 4511-42-6 [(S,S)-Lactide] Y
* 25038-75-9 [(R,R)-Lactide] N
* 13076-19-2 [(R,S)-Lactide = meso-Lactide] N
* 26680-10-4 [mixture of three isomers] Y
* 95-96-5 [mixture of three isomers][1] Y

3D model (JSmol)

* Interactive image

ChemSpider |

* 7002

EC Number |

* 202-468-3

PubChem CID

* 7272

UNII |

* IJ13TO4NO1 [(S,S)-Lactide] Y
* 9J7G894K2M [mixture of three isomers] Y
* 7EH08MWO6M [mixture of three isomers] Y

InChI

* InChI=1S/C6H8O4/c1-3-5(7)10-4(2)6(8)9-3/h3-4H,1-2H3

Key: JJTUDXZGHPGLLC-UHFFFAOYSA-N

SMILES

* CC1C(=O)OC(C(=O)O1)C

Properties

Chemical formula

| C6H8O4
Molar mass | 144.126 g·mol−1
Melting point |  95 to 97 °C (203 to 207 °F; 368 to 370 K) [(S,S)-Lactide and (R,R)-Lactide][2]

Solubility in water

| Hydrolyses to lactic acid[2]
Solubility | soluble in chloroform, methanol
slightly soluble in benzene

[2]

Hazards
GHS pictograms |
GHS Signal word | Warning

GHS hazard statements

| H319

GHS precautionary statements

| P264, P280, P305+351+338, P337+313

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

N verify (what is YN ?)
Infobox references

Tracking categories (test):

* SizeSet

Lactide is the lactone cyclic ester derived by multiple esterification between two (usually) or more molecules from lactic acid (2-hydroxypropionic acid) or other hydroxy carboxylic acid. They are designated as dilactides, trilactides, etc., according to the number of hydroxy acid residues. The dilactide derived from lactic acid has the formula [CH(CH
3)CO

2. All lactides are colorless or white solids. This lactide has attracted interest because it is derived from abundant renewable resources and is the precursor to a biodegradable plastic.[3]

## Stereoisomers

The dilactide derived from lactic acid can exist in three different stereoisomeric forms. This complexity arises because lactic acid is chiral. These enantiomers do not racemize readily.

(R,R)-Lactide (left above), (S,S)-lactide (right above) and meso-lactide (below)

All three stereoisomers undergo epimerisation in the presence of organic and inorganic bases in solution.[4]

## Polymerization

Lactide can be polymerized to polylactic acid (polylactide). Depending on the catalyst, syndiotactic or a heterotactic polymers can result. The resulting materials, polylactic acid, have many attractive properties.[5][6]

## References

1. ↑ Sigma Aldrich product page for lactide Retrieved 8th of July 2015
2. ↑ 2.0 2.1 2.2 Römpp Online Chemielexikon Version 3.3 aufgerufen am 25. März 2009
3. ↑ Andreas Künkel; Johannes Becker; Lars Börger; Jens Hamprecht; Sebastian Koltzenburg; Robert Loos; Michael Bernhard Schick; Katharina Schlegel et al. (2016). Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. pp. 1–29. doi:10.1002/14356007.n21_n01.pub2. ISBN 978-3-527-30673-2.
4. ↑ Shuklov, Ivan A.; Jiao, Haijun; Schulze, Joachim; Tietz, Wolfgang; Kühlein, Klaus; Börner, Armin (2011-03-02). "Studies on the epimerization of diastereomeric lactides". Tetrahedron Letters 52 (9): 1027–1030. doi:10.1016/j.tetlet.2010.12.094. ISSN 0040-4039.
5. ↑ R. Auras; L.-T. Lim; S. E. M. Selke; H. Tsuji (2010). Poly(lactic acid): Synthesis, Structures, Properties, Processing, and Applications. Wiley. ISBN 978-0-470-29366-9.
6. ↑ Odile Dechy-Cabaret; Blanca Martin-Vaca; Didier Bourissou (2004). "Controlled Ring-Opening Polymerization of Lactide and Glycolide". Chem. Rev. 104 (12): 6147–76. doi:10.1021/cr040002s. PMID 15584698.

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*[CID]: Compound ID
*[H319]: Causes serious eye irritation
*[P264]: Wash … thoroughly after handling
*[P280]: Wear protective gloves/protective clothing/eye protection/face protection
*[P305+351+338]: IF IN EYES: Rinse continuously with water for several minutes. Remove contact lenses if present and easy to do – continue rinsing
*[P337+313]: Get medical advice/attention